Print Microbiology Lab- Exercise 45 Bacteria of the Skin flashcards - Easy Notecards

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Microbiology Lab- Exercise 45 Bacteria of the Skin

front 1 True or false the skin is inhospitable environment for most microorganisms.	back 1 true
front 2 Dry layers of _________ containing cells make up the _______ the outermost layer of the skin an are not easily colonied by microbes.	back 2 keratin epidermis
front 3 ______ secreted by oil glands ________ _______ _______.	back 3 sebum inhibits bacterial growth
front 4 _______ in ________ create a hypertonic environment.	back 4 salt perspiration

front 5 Salt and perpsiration are nutritive for certain microorganisms and this estabishes them as part of the _____ _______.	back 5 Normal microflora
front 6 Normal microflora tends to be ______ to drying and to relatively high ______ ________.	back 6 resistant salt concentrations
front 7 Bacteria like moist areas such as the _____ and ________.	back 7 arm pits (axilla) sides of the nose
front 8 ________ microflora ar present on hands and arms in contact with the environment.	back 8 transient

front 9 True or false. Despite the adverse environment the microbial population is diverse.	back 9 true
front 10 Recent ribosomal RNA swabbing on the skin of the forehead have identified _____ species of bacteria.	back 10 40
front 11 The most common genera on the skin are ______ and ____________.	back 11 Propionibacterium Staphylococcus
front 12 Propionibacterium live in _______ on sebum from the oil glands.	back 12 hair follicles

front 13 The propionic acid they produce maintains the ______ of the skin between ____-____ which suppresses the growth of other bacteria.	back 13 pH 3-5
front 14 Most bacteria on the skin are _________ and ____________.	back 14 gram (+) and salt tolerant
front 15 Mannitol salt agar is selective for ________ ___________ and __________ in that mannitol-fermenting organisms will produce __________ turning the indicator _______.	back 15 salt tolerant organisms differential acid yellow
front 16 _________ _________ i considered part of your normal microflora and considered a ________.	back 16 Staphylococcus aureus pathogen

front 17 S. Aureus which produces _________ an enzyme that coagulates the fibrin in blood and is ______.	back 17 coagulase pathogenic
front 18 True or false. A test for the presence of coagulase is used to distinguish S. aureus from other species of Staphylococcus.	back 18 true
front 19 Why is MSA used as a selective medium for normal skin microbiota?	back 19 Because it i selective for salt tolerant organisms such as Staph
front 20 List three identifying characteristics of Staphylococcus aureus	back 20 gram-positive (purple), catalase-positive (when mixed with hydrogen peroxide it bubbles), and coagulase-positive cocci (clumps)

front 21 List three factors that protect the skin from infection:	back 21 1. the dry layers making up the epidermis are not easily colonized. 2. sebum, secreted by oil glands, inhibits growth 3. salts in perspiration create a hypertonic environment
front 22 What is coagulase? How is it related to pathogenicity?	back 22 Coagulase is a protein enzyme produced by several microorganisms that enables the conversion of fibrinogen to fibrin. In the laboratory, it is used to distinguish between different types of Staphylococcus isolates. Importantly, S. aureus is coagulase-positive, meaning that coagulase negativity excludes S. aureus. Coagulase reacts with prothrombin in the blood. The resulting complex is called staphylothrombin, which enables the enzyme protease to convert fibrinogen to fibrin. This results in clotting of the blood. Coagulase is tightly bound to the surface of the bacterium S. aureus and can coat its surface with fibrin upon contact with blood. It has been proposed that fibrin-coated staphylococci resist phagocytosis, making the bacteria more virulent. Bound coagulase is part of the larger family of MSCRAMM
front 23 The microorganisms that establish more or less permanent residence without producing diseases are known as _______ _________.	back 23 Normal microbiota (aka microflora)
front 24 Microorganisms that may be present for just a few days or months are called ____________.	back 24 transient microbiota

front 25 True or false. At one time bacteria and fungi were thought to be plants which why they are referred to as flora sometimes.	back 25 true
front 26 A microorganism that causes disease is called a ________.	back 26 pathogen
front 27 Identifying pathogens is imperative for initiating proper _________ and tracing the sources of the ______.	back 27 treatment infection
front 28 What are three essentials for identifying the microorganisms in a clinical laboratory?	back 28 morphological characteristics differential stains biochemical testing

front 29 Dichotomous keys are essential tools for sorting through lab tests identifying microorganisms in an organized manner. In a dichotomous key identification is based on successive _________ and each one has _____ possible answers.	back 29 questions 2 possible answers
front 30 Dicho means?	back 30 cut in two
front 31 MSA: S. aureus ferments __________ causing the phenol red to turn ____________.	back 31 mannitol yellow
front 32 MSA: S. epidermidis tolerates the high _________ concentration and grows on __________.	back 32 salt mannitol salt agar